Methods of the invention separate a target nucleic acid from a sample by using at least one capture probe oligonucleotide that contains a target-complementary region and a member of a specific binding pair that attaches the target nucleic acid to an immobilized probe on a capture support, thus forming a capture hybrid that is separated from other sample components before the target nucleic acid is released from the capture support and hybridized to a detection probe to form a detection hybrid that produces a detectable signal that indicates the presence of the target nucleic acid in the sample. Compositions for practicing the methods of the invention include a capture probe oligonucleotide made up a target-complementary region sequence and a covalently linked capture region sequence that includes a member of a specific binding pair.